1. Field of the Invention
This invention relates to dielectric gas-vapor and vapor-vapor compositions and, more particularly, it pertains to mixtures of a gas with the vapor from one fluid having a high vapor pressure at a low temperature and the vapor from another fluid having a low vapor pressure at a low temperature, with the objective of attaining high electrical strength over a temperature range from low temperature (.about.-40.degree. C.) to high temperature (.about.+140.degree. C.) with a vapor pressure not greater than one to two atmospheres at the highest temperature.